Electrical control apparatus



"Patented June 9, 1942 UNITED STATES E ATENT OFFICE ELECTEECAL CONTROL APPARATUS Application June 2'7, 1941, Serial No. 399,975

8 Claims.

My invention relates to electrical control apparatus, and it has particular reference to electrical control apparatus of the type adapted for use in railway signal systems. More particularly, my invention relates to the provision of electrical control apparatus involving an improved form of a multiple position direct current relay, and means for controlling and utilizing such a relay.

In general, it is proposed in accordance with my invention to provide a four-position direct current relay comprising an operating or neutral winding for operating a neutral armature, and one or more polarizing windings for polarizing a polar armature, biased to a neutral midposition and caused to operate to one operated position or another according as the currents in the operating and polarizing windings are of one relative polarity or the other, respectively. Cooperating with such a relay are circuit means arranged to be effective at times to energize the operating windings but not the polarizing windings, whereby to cause operation of the neutral armature without affecting the polar armature, and at other times to energize both the operating and polarizing windings, whereby to effect operation of both the neutral and polar armatures.

More specifically, it is proposed in accordance with my invention to provide a four-position direct current relay adapted to replace the usual three decoding relays employed in coded railway signal systems. The three decoding relays employed usually comprise a code detecting relay, a relay selectively responsive to current of the approach restricting or I20 code, and a relay selectively responsive to the clear or I89 code The circuit arrangements controlling the relays are such that when no coded current is available, all relays are released; when the caution or E code is available, the code detecting relay is energized but the other two relays are released; and when either of the other two (approach restricting or clear) codes is available, both the code detecting relay and the one of the two code selecting relays, corresponding to the particular code rate available, are energized and picked up while the other code selecting relay is released, A relay embodying my present invention, when incorporated into a control system of the type described, has its operating or neutral windings arranged to function as the code detecting relay, and has two polarizing windings corresponding respectively to the two code selecting relays, with the polarity of current supplied to the two polarizing windings selected to reversibly operate the polar armature of the relay.

In view of the foregoing and other important considerations, it is an object of my invention tinctive control positions.

A further object is to provide a four-position direct current relay adapted to replace the usual three decoding relays employed as decoding relays in coded railway signal systems.

An additional object is to provide novel and improved decoding apparatus for coded railway signal systems.

Another object is to provide novel and improved electrical control apparatus involving a four-position direct current relay and means for controlling and utilizing such a relay.

Other important objects and characteristic features of my invention will be pointed out in the following description.

I shall describe one form of apparatus embodying my invention, and shall then point out the novel features thereof in claims.

In the accompanying drawing, Fig. 1 is a diagrammatic view illustrating one form of electrical control apparatus embodying my invention utilized to decode coded track circuit current in a railway signal system. Figs. 2 and 3 are diagrammatic views each illustrating different control positions assumed by the armatures of relay R shown in Fig. 1. In each of the several views, similar reference characters have been employed to designate corresponding parts.

Referring to the drawing, the reference charactors I and la designate the track rails of a stretch of railway track divided by insulated joints 2 into an insulated track section D-E. The rails of the section are supplied with coded track circuit current in the usual manner by means of a track transformer TT which has its secondary winding connected across the track rails and has its primary winding supplied with alternating current from a suitable source indicated by the reference characters BX and CK. A code transmitter or coder C'I operating a plurality of coding contacts 15, I20 and at the rates of, say, 75, and times per minute, respectively, has its contacts interposed'jone in each of a plurality of circuits over which current is supplied to transformer TT. Inaccordance with certain predetermined conditions, one or another of the above-mentioned contact members operated by coder CT is conditioned to interrupt periodically or code the current that is supplied to the rails of section DE, and as indicated in the drawing, the rate at which such current is coded is selected by suitable traffic controlled apparatus responsive to trafiic conditions on the stretch. The details of the trafiic controlled apparatus are not shown in the drawing since the particular form of such apparatus forms no part of my present invention, but such apparatus may take any one of the forms of wayside decoding apparatus well known in the art, or may be similar to the decoding apparatus hereinafter described in detail. It is deemed sufficient to state that in accordance with the customary practice, contact I89 is rendered effective to code the current supplied to transformer TT under clear trafiic conditions in the stretch; contact I2!) is rendered effective to code the current under approach restricting conditions in the stretch; and contact is selected to code the current under caution trafiic conditions in the stretch.

In connection with a stretch of railway track supplied with coded track circuit current, I provide novel and improved electrical control apparatus operative to decode the coded energy, and have represented such apparatus incorporated into a train-carried control system shown provided for a train W illustrated as occupying section D-E. The train W, as shown, is provided with the usual two receiving coils 4 and 5 carried by the train in advance of its first pair of wheels and located in inductive relation with the track rails I and la, respectively. These coils are connected in series in such manner that the voltages induced therein by alternating current flowing in opposite instantaneous directions in the rails I and la are additive, and the coils are connected through the medium of the usual amplifier A to a master code following relay MR. To accord with the usual practice, I shall assume that relay MR is constructed and arranged so as to cause its armature B to be operated to its upper or front position in response to each on interval of code when energy is received from the track rails, and to cause its armature 6 to be operated to its back or released position during each off interval of the code when no energy is received from the track rails.

Associated with relay MR is a decoding transformer DT comprising a primary winding 9 and secondary windings l0 and II. When relay MR is operated by an on impulse of current, a portion of primary winding 9 is supplied with current from a suitable source, such as a battery not shown but having its opposite terminals represented by the reference characters B and C, .over an obvious circuit including front contact 6-1 of the relay, and when relay MR closes its contact 68 during an off interval of the code,

another portion of primary winding 9 is enersingle four-position direct current relay R com.

prising a magnetizable core having two outer legs l5 and l! and a relatively shorter intermediate leg IS, a backstrap l8 connecting the legs together at one end, a neutral armature l9 arranged, for example as by pivoting the armature in the usual manner not shown, to operate toward and away from the other ends of the core legs and biased as by gravity to a released position away from the core legs, and a polar armature 20 pivoted at 2| in a bifurcated lower portion of the middle core leg and biased, as by springs 22, to a neutral mid position in which it is represented in Fig. 1. Relay R also comprises a neutral or operating wind ing consisting of two coils 24, 24 disposed one coil on each outer leg of the core and connected in series in such manner that when energized the coils cooperate in circulating flux through a magnetic path indicated in Fig. 1 and comprising in series relation outer leg l5, backstrap l8, outer leg I! and armature l9. It follows, therefore, that when operating winding 24 is energized, neutral armature I9 is operated toward the core to an attracted position, as shown in Fig. 1, and when winding 24 is deenergized, armature I9 operates away from the core to a back or released position. Neutral contact members, such as members 26, 21 and 28, are operatively connected with armature [9 in the usual manner indicated by a dotted line in the drawing, and such contact members are caused to cooperate with the usual contact points to form front contacts or back contacts according as armature I9 is picked up or released, respectively.

The two outer core legs l5 and ll of relay R, as shown, are provided with lugs or auxiliary pole faces which project inwardly toward each other in a line below pivot 2| of armature 20. The middle leg I6 of the core is provided with one or more polarizing windings, two windings 29 and 39 being illustrated in the drawing. When operating winding 24 is energized, and polarizing winding 29 is energized by current of a polarity selected to cause winding 29 to circulate flux upwardly through core leg It, as viewed in the drawing, the fiux due to current in winding 29 circulates through a magnetic circuit indicated by dash lines in Fig. 2 and comprising in series relation leg l6, backstrap l8, leg I1 and its projection, and armature 29. Polar armature 20 accordingly is caused to swing in a clockwise direction, as viewed in the drawing, or toward the projection on leg H, as illustrated in Fig. 2.

If, now, the direction of the polarizing flux threading leg I6 is reversed, as by deenergizing winding 29 and energizing winding 39 with current having a polarity selected to circulate flux downwardly through leg l6, this polarizing flux circulates through a magnetic circuit indicated in dash lines in Fig. 3 and comprising in series relation leg l6, armature 29, the projection of and core leg l5, and backstrap I8. Armature 20 accordingly is caused to swing in a counterclockwise direction or toward the projection on leg 15, as represented in Fig. 3.

The relay R may readily be modified to employ only one polarizing winding, such as winding 29. With such a relay, the polar armature 29 may be reversibly operated by reversing the polarity of current supplied to the polarizing winding. That is, when operating winding 24 is energized by current of a constant polarity, armature 29 is caused to swing in a clockwise or a counterclockwise direction dependent upon the relative polarity of current supplied to winding 29. Conversely, the polarity of current supplied to winding 29 may be maintained constant and the polar armature may be caused to swing in a clockwise or a counterclockwise direction according to the relative polarity of current supplied to the operating winding. In either case, operation of the polar armature is dependent upon energizing both the operating and the polarizing windings since with the operating winding deenergized and the polarizing winding energized, the two magnetic circuits for the polarizing flux, through the two outer core legs I and H, are in multiple and with equal air gaps between armature 2i] and the projections on legs I5 and H, the flux will divide equally in the two circuits, thus causing the attractive actions on the outer ends of armature 29 to be of equal magnitude and thereby tending to hold armature 20 in its biased mid position. Operation of the neutral armature under such assumed conditions is not, of course, effected by the flux due to current in the polarizing winding.

Armature 2% has associated therewith contact members arranged in such manner that one set 1 of contacts is closed when the armature is in its biased mid position, another set of contacts is closed when the armature is caused to swing in a clockwise direction or toward the projection of leg El, and still another set of contacts is closed when the armature is caused to swing in a counterclockwise direction or toward the projection of the other leg it. These contact members are operatively connected to armature 28, as indicated in the drawing by a dotted line, and comprise, for example, polar contact members 32 and 33 and a biased intermediate contact member 34, secured to an insulating member 35 operatively connected to armature 25. Contact nember 34 is U -ehap-ed or bifurcated and is carried by armature member 35 in such manner that in the biased intermediate position of armature 20, one leg of member engages a contact point 38 while the other leg of the member engages another contact point 31, thereby providing a contact 353-31 closed, as represented in Fig. l, in the neutral or biased position of the polar armature. One polar contact member 32 carried by member 35 is caused to engage a contact point 38 to form a polar contact 32-48 when armature 2B is swung clockwise or toward leg IT, as shown in Fig. 2. In this position of the armature, dependent contact member 34 is swung away from contact point 3?, thereby breaking contact 3ii3431. The other polar contact member 33 carried by member 35 is caused to engage a contact point 39 to form a polar contact 33-49 when armature 253 is swung in a counterclockwise direction or toward the projection of leg 55, as shown in Fig. 3, In this position of the armature, the dependent contact member 34 is operated out of engagement with contact point 35, thereby breaking contact 36-34-31.

Relay R is incorporated into the train-carried decoding apparatus in such manner that operating winding 2 is connected to secondary winding ID of transformer DT through the medium of a full-wave rectifier 4|; one polarizing winding 29 is connected through a decoding unit DUIZG to secondary winding i! and the other polarizing winding 3%] is connected through another decc-ding unit DUKES also to winding ll. The details of construction of the decoding units DUIZil and DUiBil are not shown in the drawing, but such units usually comprise a rectifier and a reactor condenser tuning unit tuned to resonance at a frequency corresponding to the 120 and I8!) code rates, respectively, whereby wind-ing 29 iseffectively energized by unidirectional current, supplied through decoding unit DUIZil, when and only when relay MR responds to current coded at-the I20 code rate, and winding 39 is eiiectively energized by unidirectional current supplied through decoding unit DUISB, when and only when relay MR operates at the I code rate. The connection of operating Winding 24 to secondary winding H1 is untuned, hence operating winding 24 is supplied through rectifier 4| with unidirectional current and is effectively energized whenever relay MR operates at any one of the previously mentioned code rates. It is readily apparent that the circuit means provided for relay R is arranged so that operating winding 24 may be energized, as when relay MR fol-lows 15 code, without effectively energizing either of the two polarizing windings 29 and 5B, and that when either polarizing winding is effectively energized, as when relay MR follows either I20 or I80 code current, the operating winding 24 also is energized. It follows, therefore, that relay B may be operated to any one of four positions, in a first of which the operating and polarizing windings are deenergized, neutral armatur i9 is released and polar armature 26 is caused to assume its biased mid position; in a second of which the operating winding is energized, neutral armature i9 is picked up, polarizing windings 2E; and 3t are cleenergized, and polar armature 20 is in its biased mid position; in a third position of which operating winding 24 and one polarizing winding 29 are energized by current having a relative polarity such as to cause polar armature 28 to swing clockwise, and neutral armature I9 is picked up; and in the fourth position of which operating winding 25 and the other polarizing winding 3d are energized by current of a relative polarity such as to cause polar armature 2D to swing in a counterclockwise direction, and neutral armature id is picked up.

The control apparatus hereinbefore described may be utilized to control suitable train controlling means, suchas, for example, a four-indication cab signal CS comprising four lamps 43, 44, 45 and 46. When relay MR. is inactive and operating winding 24 and polarizing windings 29 and 3b are deenergized, neutral armature I9 is released and back contact 28 operated thereby is closed to complete an obvious circuit for lamp 43 of signal CS. Such lamp may, for example, be utilized as the customary slow speed indication of the signal. When current of the 15 code is available in the section and relay MR operates at a corresponding rate, operating winding 24 is energized and neutral armature I9 is picked up to close front contact 28. The two polarizing windings 29 and 3|] are deenergized at this time, hence polar armature 20 is in its biased mid position and closes contact 35*34-31 to energize lamp 44 over an obvious circuit, including that contact and front contact 28 operated by the neutral armature. This lamp may be utilized as the customary caution aspect of the signal.

When current of the i2!) code is available in the section and relay MR operates at a corresponding rate, operating winding 24 is energized to pick up neutral armature I5 and close front contact 21, and polarizing winding 29 also is effectively energized by current having a polarity with relation to the current in winding 24 such that polar armature 29 is swung in a clockwise direction to close polar contact 32-38, Lamp &5 accordingly becomes energized over an obvious circuit including front contact 21 operated by neutral armature l9 and polar contact 3238 operated by polar armature 20. This lamp may be utilized as the customary approach restricting aspect of the signal.

Whenever I80 code current is available in the rails and relay MR operates at the corresponding rate, operating winding 24 is energized and causes neutral armature 9 to be picked up to close its front contact 26, while polarizing winding 30 is effectively energized by current having a polarity, with respect to current in the operating winding, such that polar armature 20 is swung counterclockwise toclose polar contact 33-39 and energize lamp 46 of signal CS over an obvious circuit including front contact 26 of neutral armature l9 and polar contact 33-49 operated by the polar armature. This lamp may be utilized as the customary clear indication of the cab signal.

From the foregoing, it is evident that I have provided novel and improved electrical control apparatus involving a four-position direct current relay and arranged to be particularly effective for use in decoding coded track circuit current. It is, of course, to be understood that while apparatus embodying my invention has been illustrated and described in connection with a railway signal system, such use represents only one of the many applications where such apparatus may be employed.

Although I have herein shown and described only one form of electrical control apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a four-position direct current relay comprising a magnetizable core having an operating winding for causing a neutral armature to move toward and away from said core, a polarizing winding disposed on said core, a polar armature biased to a mid position and caused to operate to one extreme position or the other according as the flux due to current in said polarizing winding has one relative polarity or the other with respect to flux due to current in said operating winding, and circuit means for at times energizing said operating winding but not said polarizing winding and at other times energizing said operating winding and said polarizing winding with current having one relative polarit or the other.

2. In combination, a four-position direct current relay comprising a three-legged core structure provided with operating windings on the two outer core legs and a polarizing winding disposed on the remaining third leg of the core, circuit means for energizing said operating windings and for at times energizing said polarizing winding with current of one relative polarity or the other, a neutral. armature disposed in the field of said operating windings for movement toward and away from said core, neutral contacts operated by said neutral armature, a polar armature disposed in the field of said polarizing winding for swinging movement toward one or the other of said outer core legs dependent upon the relative polarities of current in said operating and polarizing windings, means for biasing said polar armature to a mid position intermediate said two outer core legs when said polarizing winding is deenergized, contacts operated by said polar armature and closed when said polar armature is swung toward one or the other of said outer core legs, and other contacts operated by said polar armature and closed when said polar armature is in its said biased mid position, whereby to provide means for effecting four distinct control conditions, one when said operating winding is deenergized, another when said operating winding is energized, a third when said operating and polarizing windings are energized by current of the same relative polarity, and a fourth when said operating and polarizing windings are energized by current of opposite relative polarity.

3. In combination, a four-position direct current relay comprising a magnetizable core having an operating winding, a neutral armature actuated by said operating winding and provided with contacts, a polarizing winding on said core, a polar armature biased to a mid position and having contacts closed in said mid position, said polar armature being caused to operate to one extreme posit-ion or another according as said operating and polarizing windings are energized by currents having one relative polarity or the other, and contacts operated by said polar armature and selectively closed in on or the other of said extreme positions.

4. In combination, a four-position direct current relay comprising a magnetizable core having an operating winding, a neutral armature actuated by said operating winding and provided with contacts, a polarizing winding on said core, a polar armature biased to a mid position and having contacts closed in said mid position, said polar armature being caused to operate to one extreme position or another according as said operating and polarizing windings are energized by currents having one relative polarity or the other, contacts operated by said polar armature and selectively closed in said one and said other extreme position, and circuit means for at times energizing said operating winding but not said polarizing winding and at other times energzing said operating and polarizing windings with currents having one relative polarity or the other.

5. Electrical control apparatus comprising a four-position direct current relay, an operating winding and a polarizing winding for said relay, a neutral armature operated by said oper ating winding, contacts operated by said neutral armature, a polar armature biased to a mid position and caused to be operated to one extreme position or another according to the relative polarities of the fluxes due to currents in said operating and polarizing windings, contacts operated by said polar armature and selectively closed in said biased mid position and in each of said extreme positions of said polar armature, circuit means for at times energizin said operating winding but not said polarizing winding and at other times for energizing said operating and polarizing windings with currents having either relative polarity, and means selectively controlled by said contacts of said neutral armature and by said contacts of said polar armature.

6. Decoding apparatus for use in coded systems of railway signaling, comprising the combination with a decoding transformer having means for supplying unidirectional current to a first circuit when said transformer is energized at any of the usual code rates, and having other means for supplying unidirectional current to a second circuit or a third circuit according as said transformer is energized at one or another of a particular two of said usual code rates, a single decoding relay having an operating winding receiving energy from said first circuit, a neutral armature operated by said operating winding, said relay having two polarizing windings one receiving energy from said second circuit and the other winding receiving energy from said third circuit, and a polar armature biased to a mid position and having contacts closed in said mid position as well as polar contacts selectively closed in one or the other of two operated positions, the polarity of current supplied to said polarizing windings from said other means being selected to reversibly operate said polar armature provided that said operating winding is energized.

'7. In combination with a railway track supplied with track circuit current coded at one or another of a plurality of code rates, receiving means operated by said track circuit current and including means for supplying energy to a first circuit whenever said receiving means operates at any one of said code rates and other means for supp-lying energy to a second circuit or a third circuit according as said receiving means operates at one or another of a selected two of said plurality of rates, decoding means comprising a single four-position relay having an operating winding receiving energy from said first circuit and two polarizing windings one receiving energy from said second circuit and the other receiving energy from said third circuit, a neutral armature operated by said operating winding, a polar armature biased to a mid position and having contacts closed in said mid position as Well as polarcontacts selectively closed in one or the other of two operated positions of said polar armature, the polarity of currents supplied to said polarizing windings from said second and third circuits being selected to cause said polar armature to operate to one or the other of said two operated positions according as one or the other of said two polarizing windings is energized when said operating winding is energized, and railway traffic controlling apparatus selectively controlled by contacts of said neutral armature and by said contacts of said polar armature.

8. A coded system of railway signaling of the class wherein track circuit current coded at one or another of a plurality of code rates is supplied to the rails of a stretch of track for selec tively controlling railway trafiic controlling apparatus in accordance with the code rate of the track circuit energy, through the medium of decoding apparatus supplied with energy from code operated apparatus receiving energy from the rails and including means for supplying energy to a first circuit when said code operated apparatus operates at any one of said plurality of code rates and to a second circuit or a third circuit according as said code operates apparatus operated at one or another of a selected two of said plurality of code rates, said decoding apparatus comprising a single four-position relay having an operating winding receiving energy from said first circuit and two polarizing windings one receiving energy from said second circuit and the other receiving energy from said third circuit, a neutral armature operated by said operating winding, a polar armature biased to a mid position and having contacts closed in said mid position as well as polar contacts selectively closed in one or the other of two operated positions of said polar armature, the polarity of currents upplied to said polarizing windings from said second and third circuits being selected to cause said polar armature to operate to one or the other of said two operated positions according as one or the other of said two polarizing windings is energized when said operating winding is energized, and railway traffic controlling apparatus selectively controlled by contacts of said neutral armature and by said contacts of said polar armature.

BENJAMIN MISHELEVICH. 

